The effect of corrugation height on flow in a wavy-walled pipe

Abstract

We have used direct numerical simulation to examine both laminar and turbulent flows in circular pipes with smoothly corrugated walls, where the corrugation wavelength has been kept constant at 0.419D, and the corrugation height was varied from zero to 0.08D. Flow rates have been varied in steps between low values that provide laminar flow, up to higher values where the flow is turbulent: the maximum bulk flow Reynolds number for the smooth pipe was Re D =UD/ν = 10×10 3, giving a friction Reynolds number Re τ = 314. Even in the laminar regime, the larger corrugation heights produce flow separation, and the proportion of pressure drop that is attributable to pressure drag can be of order 50%,..